Stun grenades, or “flash-bang” devices are used by military and law enforcement as non-lethal devices intended to distract or stun dangerous suspects or adversaries. Such devices are deployed to minimize hostile responses, and to generate compliance.
A typical existing device employs a “single bang” provided by a quantity of flash-charge material (such as a mixture of aluminum powder and potassium perchlorate) that is detonated after a brief delay. A fuse is activated by release of a handle as in a typical grenade, and the fuse ignites a column of delay material (such as black powder or Zirconium Nickel). The column provides a delay (typically ½ second) until the flame front in the delay material reaches an aperture that communicates with the flash-charge material, igniting it to provide a bright flash and loud report.
One such device is shown in U.S. Pat. No. 5,654,523 to Brunn, titled “Stun Grenade.”This “single-bang” device has an advantageous configuration. Like many others, it is a cylindrical body sized to readily be gripped by an adult hand, so that the device is secure in the user's fist, with the ends of the cylinder protruding beyond each end of the user's fist. The disclosed device has the advantage that all the vent holes for releasing the energy of the flash charge material come out the ends of the grenade body. While a device normally discharges only after a delay following release by the user, there is a remote possibility that the grenade may discharge while still in the user's hand, such as if the user is distracted, or the device snags on the user's glove. The disclosed device minimizes the risk of serious injury in such an event by discharging the combustion gases out the ends of the device, with no apertures in the cylindrical sidewall of the device.
Other devices have sought to provide added tactical effectiveness by employing a device with multiple reports in a single grenade. Such a device is shown in U.S. Pat. No. 7,963,227 to Brunn, titled “Multiple Report Stun Grenade.” This device provides a timed sequence of activating flash charges by positioning passages at different locations along a central column. Upon discharge, gases and materials escape from openings at both ends of sleeves so the motive forces generated by expelled gases will be balanced. The Brunn '227 device has the disadvantages of being complex and expensive to manufacture. The Brunn '227 device is also potentially vulnerable to having cross-contamination of pressure gradients causing sympathetic communication between explosion events. Unexpected charge initiation events can also be caused by issues with flame communication from the center delay column to the charge tubes. The center delay column is wide and the burn front is uncontrolled as it progresses. Because the tubes that communicate the flame to the charge tubes are closer together than the possible flame front irregularities, it is possible that the charges can go off out of order. The communication tubes are also small, so it is also possible the flame communication may be delayed to one or more charges, again causing the charges to go off out of order.
Therefore, a need exists for a new multiple report stun grenade that provides reduced likelihood of cross-contamination of pressure gradients causing sympathetic communication between explosion events. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the multiple-report stun grenade according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of reducing the likelihood of cross-contamination of pressure gradients causing sympathetic communication between explosion events.